In the last few years the entertainment industry begun a transformation from being strictly a provider of analog information to a provider of digital information. For example, while phonograph records and prerecorded analog audio tapes were the predominate media for the distribution of music, today the compact disk and digital audio tape (DAT) are the preferred media for distribution. The retail channel for prerecorded products has also begun to change. Where a consumer could only acquire a music or audio product from a retail store in the past, today many other distribution channels are available. Home cable systems provide pay-per-view services to consumers for movies and the like. Satellite systems provide pay-per-view home services also for those without cable. While the cable and satellite systems generally use analog technology, with the advent of direct broadcast satellites (DBS) and newer wide bandwidth fiber cable systems, digital technology will become the predominant technology for entertainment and information distribution. Soon most people will have access to a fiber cable or satellite distribution system capable of sending high quality images and audio on demand. The age of the "information highway" has begun.
One reason for the conversion from analog to digital distribution is that while analog systems degrade the information being transferred, digital systems do not. A commonly understood example of analog technology is the VCR. When a copy of a movie is made from one VCR to another VCR, the image and audio copied is not quite as good as the original. If successive generations of the movie are made from prior generation copies, at some point, the result will be a copy of the movie that is not viewable and the sound track will be very distorted if audible at all.
On the other hand, digital copying is perfect. Every copy will be just as good as the original. For this reason Congress recently passed laws aimed at limiting the ability of a person to make unlimited copes of a prerecorded DATs. However these laws address only the DAT copy issue and not the general issue of copying digital information. Also, it is unlikely that someone making a great deal of money from the illegal copying and distribution of audio and video products will be particularly deterred by an inconvenient law.
The information highway is useful for distributing other information besides movie and music products. For example to transfer high quality still images or a newspaper, the use of a lossless distribution system is highly desirable making a digital distribution system ideal. Since most things a human can see or hear can be converted to digital information, it is useful to think of the digital information as representing an "object". The object may be a still picture, a song or anything else that can be represented digitally. So while the object can easily distributed by a digital highway, the issue of how to protect the object from unauthorized copying remains a significant problem.
The issue of copying is even more of a problem with the information highway than in the past. An object provider will use the information highway to deliver a "perfect" copy of an object, on demand, to a customer. That is the customer will have the object in digital form. Therefore the customer will be able to make unlimited "perfect" copes of the object. An unscrupulous customer (pirate) can then make and sell copes of the object at the expense of the owner of the object. To prevent such copyright infringement, a method and apparatus is needed to allow the owner of an object to distribute the object in digital form while providing a way for the owner to hold an illegal copier accountable.